1. Field of the Invention
This invention is related to wellbore milling processes; milling tools and whipstocks and anchors for them; and in one aspect to single-trip milling methods and systems.
2. Description of Related Art
Milling tools are used to cut out windows or pockets from a tubular, e.g. for directional drilling and sidetracking; and to remove materials downhole in a well bore, such as pipe, casing, casing liners, tubing, or jammed tools. Various prior art tools have cutting blades or surfaces and are lowered into the well or casing and then rotated in a cutting operation. With certain tools, a suitable drilling fluid is pumped down a central bore of a tool for discharge beneath the cutting blades to assist in the removal from the well of cuttings or chips.
Milling tools have been used for removing a section of existing casing from a well bore to permit a sidetracking operation in directional drilling, to provide a perforated production zone at a desired level, to provide cement bonding between a small diameter casing and the adjacent formation, or to remove a loose joint of surface pipe. Also, milling tools are used for milling or reaming collapsed casing, for removing burrs or other imperfections from windows in the casing system, for placing whipstocks in directional drilling, or for aiding in correcting dented areas of casing or the like. Prior art sidetracking methods use cutting tools of the type having cutting blades and use a deflector such as a whipstock to cause the tool to be moved laterally while it is being moved downwardly in the well during rotation of the tool, to cut an elongated opening pocket or window in the well casing.
Certain prior art operations which employ a whipstock also employ a variety of tools used in a certain sequence. That requires a plurality of xe2x80x9ctripsxe2x80x9d into the wellbore. For example, a false base (e.g. a plug, bridge plug, packer or anchor packer) is set in a casing or in a borehole that serves as a base on which a whipstock can be set. Certain prior art whipstocks have a movable plunger which acts against such a false base. In certain multi-trip operations, a packer is oriented and set in a wellbore at a desired location. This packer acts as an anchor on or against which tools above it may be urged to activate different tool functions. The packer typically has a key or other orientation indicating member. The packer""s orientation is checked by running a tool such as a gyroscope indicator into the wellbore. In this case a whipstock-mill combination tool is then run into the wellbore by first properly orienting a stinger at the bottom of the tool with respect to a concave face of the tool""s whipstock or by using an MWD tool. Splined connections between a stinger and the tool body facilitate correct stinger orientation. A starting mill is secured at the top of the whipstock, e.g. with a setting stud and nut. The tool is then lowered into the wellbore so that the packer engages the stinger and the tool is oriented. Slips extend from the anchor and engage the side of the wellbore to prevent movement of the tool in the wellbore. Pulling or pushing on the tool then shears the setting stud, freeing the starting mill from the tool. Rotation of the string with the starting mill rotates the mill. The starting mill has a tapered portion which is slowly lowered to contact a pilot lug on the concave face of the whipstock. This forces the starting mill into the casing to mill off the pilot lug and cut an initial window in the casing. The starting mill is then removed from the wellbore. A window mill, e.g. on a flexible joint of drill pipe, is lowered into the wellbore and rotated to mill down from the initial window formed by the starting mill. Typically then a window mill with a watermelon mill mills all the way down the concave face of the whipstock forming a desired cut-out window in the casing. This may take multiple trips. Then, the used window mill is removed and a new window mill and string mill and a watermelon mill are run into the wellbore with a drill collar (for rigidity) on top of the watermelon mill to lengthen and straighten out the window and smooth out the window-casing-open-hole transition area. The tool is then removed from the wellbore. The prior art also discloses a variety of single-trip milling systems each of which requires that a packer, bridge plug, anchor packer, or other securement be provided as a base in a tubular upon which to position the milling.
The prior art also discloses a variety of single trip setting systems for whipstocks, usually hydraulically actuated, each of which allows circulation usually only once at setting depth, after which time pins are usually sheared and any additional pumping will only pressurize the system to actuate hydraulic setting devices.
There has long been a need for an efficient and effective single trip whipstock setting method that allows for selective pressurization or circulation while fluid is being pumped through the drillstring, and also selectively provides or prevents communication between the inside and outside of the drillstring while no fluid is being pumped through the drillstring. There has long been a need for systems effecting such a method, as well as tools useful in such a method.
There has long been a need for an efficient and effective single-trip milling method and systems for effecting the method. There has long been a need for tools useful in such a method. There has long been a need for such systems which do not require a base upon which the system is emplaced and/or which have a selectively settable anchor apparatus which does not require the dropping of a ball, dart, etc.
The present invention, in one embodiment, discloses a system for selectively anchoring a wellbore tool at a desired location in a wellbore or tubular member such as casing or tubing. In one aspect the system has a selectively settable anchor assembly that has a piston that is moved upwardly by fluid under pressure from the surface. The piston moves apparatus that pushes one or more movable slips out from a body of the anchor assembly to set the anchor assembly in place.
In one aspect the system as described above has a whipstock connected to the anchor assembly. Fluid under pressure flows to the anchor assembly through the whipstock and/or through tubing on the exterior of the whipstock. In one aspect the whipstock is selectively releasably connected to the anchor assembly. In one aspect a mill (or mills) is releasably connected to the whipstock. In one aspect, fluid under pressure flows through the mill(s) to the whipstock (e.g. but not limited to through a channel in a mill, through a shear stud, through a pilot lug on the mill, and through a channel through the mill intercommunicating with the anchor assembly) or fluid under pressure flows through the mill, through exterior tubing to the whipstock, and through the whipstock to the anchor assembly.
In one aspect a selectively actuable valve assembly is provided according to the present invention for selectively controlling the flow of fluid under pressure from an inlet end of the valve assembly out through an outlet end thereof. In one aspect such a valve assembly has a rotatable ratchet sleeve which (in being moved upwardly or downwardly by members responding to increased or decreased fluid pressure) rotates to selectively maintain the valve assembly in a plurality of positions so that fluid under pressure either flows through selected ports to selected flow lines or does not flow at all. In one aspect such a valve assembly is used with a system as previously described to selectively provide actuating fluid under pressure to an anchor assembly as described to set the movable slip(s) thereof and, in one aspect, to then provide jetting fluid to jetting ports of the mill(s).
The present invention teaches, in certain embodiments, a system as described herein wherein the valve assembly of the system provides selective circulation or pressurization while a pump at the surface is engaged, the pump providing fluid under pressure to the valve assembly; such a system that provides fluid communication between the inside and the outside of the drillstring while the pumps are not pumping fluid under pressure; such a system wherein the system may be run in the hole on a drillstring so that the drill string fills up with fluid from outside the system that flows into the system to the interior of the drillstring through the system, e.g., to inhibit buoyancy of the drillstring in the hole; such a system which does not require that anything be dropped down thereinto in order to actuate parts of the system or provide for flow of fluid under pressure to and through selected desired conduits and channels; a valve assembly as shown or described herein and such a valve assembly with mill(s) releasably attached thereto, directly or indirectly, the valve assembly in fluid communication with the mill(s); such a valve assembly with a whipstock interconnected therewith, directly or indirectly, and in fluid communication therewith; such a valve assembly interconnected with, directly or indirectly, an anchor assembly as shown or described herein, the valve assembly in fluid communication with the anchor assembly; and an anchor assembly as shown or described herein with a mill and/or whipstock and/or valve assembly as shown or described herein interconnected therewith and in fluid communication therewith.
The present invention, in certain embodiments, discloses a milling system for milling an opening in a tubular in a tubular string in a wellbore extending down from a surface of the earth, the milling system having an anchor assembly to set the milling system in the tubular, a whipstock connected to the anchor assembly, a mill apparatus releasably connected to the whipstock, the mill apparatus having auto fill apparatus therein that opens when the milling system is introduced into the wellbore to permit fluid in the wellbore to enter through the mill into the tubular string, and a valve assembly connected at a top end thereof to the tubular string and at a bottom end thereof to the mill apparatus for selectively controlling fluid flow from the surface to the anchor assembly; such a system with a lug/ratchet slot system having the plurality of position recesses including recesses corresponding to an at rest position of the system in which the at least one first valve flow port and the at least one piston flow port are aligned so that as the system is run into the wellbore fluid in the wellbore is permitted to fill the system, a circulate position of the system wherein the at least one piston flow port is aligned with the at least one second valve flow port so that fluid in the piston pumped down from the surface is flowable out from the hollow body, and a set anchor position of the system in which the at least one piston flow port is aligned with the top end of the body channel so that fluid pumped from the surface is flowable past the ratchet sleeve in a channel within the hollow body and out from the hollow body to the anchor assembly to set the anchor assembly; such a system wherein the valve assembly has a plurality of recesses consisting of four recesses in sequence, a first at rest recess corresponding to a first at rest position and mode of operation, a circulate recess corresponding to a circulation position and mode of operation, a second at rest recess corresponding to a second at rest position and mode of operation, and an anchor set recess corresponding to an anchor setting position and mode of operation; such a milling system wherein a fluid pressure level within the milling system indicates that the milling system is in either a pressured up status for anchor setting or at a pressure level for fluid circulation so that inadvertent anchor setting is avoided; and such a milling system with the auto fill apparatus further having the mill apparatus having a flow bore therethrough, a ball seat releasably secured in the flow bore of the mill apparatus by a shearable member. The present invention, in certain embodiments, discloses a mill with a mill body with a top end and a bottom end, a flow bore through the mill body, at least one port in fluid communication with the flow bore and through which fluid is flowable from within the mill to an exterior thereof and from the exterior thereof to within the mill, and auto fill apparatus in the flow bore above the at least one port. The present invention, in certain embodiments, discloses a valve assembly for selectively controlling fluid flow through a hollow tubular in a string of hollow tubulars in a wellbore extending from a surface of the earth into the earth, the valve assembly with a hollow body with a hollow piston mounted for reciprocal up and down rotative movement therein, the hollow body having an inwardly projecting lug, the hollow piston having at least one piston fluid flow port therethrough and the hollow body having at least two body fluid flow ports therethrough, a ratchet sleeve connected to the piston, the ratchet sleeve having a branched slot therearound which is movable on the lug so that the ratchet sleeve and the piston are movable to a plurality of positions, the branched slot with a plurality of position recesses, at least one position in which fluid is flowable from within the hollow body to an exterior thereof and at least one position in which fluid is flowable from outside the hollow body thereinto, the positions limited to at rest, circulate, and anchor set positions so that a fluid pressure indication at the surface indicates only either a pressured up position for anchor setting or a pressured up position for fluid circulation. The present invention, in certain embodiments, discloses a milling system with a mill having a top and a bottom and mill flow bore therethrough extending down from the top thereof, a sub with a top and a bottom and a sub bore therethrough connected at the top of the mill and in fluid communication therewith, a valve in the sub bore permitting fluid flow down through the sub and preventing fluid flow up through the sub, an exit hole in the mill body in fluid communication with the mill flow bore, a rupture disc closing off the mill flow bore and disposed beneath the exit hole so that a charge of fluid is disposable between the valve and the rupture disc; and such a mill system wherein the charge of fluid is clean fluid and the milling system has a wellbore device connected to the mill and in fluid communication with the exit hole so that the charge of clean fluid is movable down to the wellbore device to activate the wellbore device. The present invention, in certain embodiments, discloses a float valve for use in wellbore operations, the float valve with a body with a top and a bottom and a fluid flow bore therethrough, a valve seat on the body, a valve member movably secured to the body for movement to seat against the valve seat to close off flow through the float valve and for movement away from the valve seat to permit fluid flow through the float valve, and a vent hole through the valve member for releasing fluid pressure build up beneath the valve member. The present invention, in certain embodiments, discloses a fill sub with a hollow body with a top, a bottom, a flow bore therethrough from top to bottom, and a fill port through the body permitting fluid communication from an exterior of the body into the flow bore, a fill valve assembly in the hollow body, the fill valve assembly having a first bore and a second bore, the first bore in fluid communication with the fill port and having a ball seat, a ball movably mounted in the first bore, an urging member mounted in the first bore in contact with the ball and releasably urging the ball against the ball seat, the ball movable away from the ball seat in response to fluid entering through the fill port and overcoming force of the urging member so that fluid from the exterior of the fill sub may enter and pass through the fill sub, the second bore in fluid communication with the flow bore so that fluid is flowable from the top of the body, through the flow bore, through the second bore, back into and through the flow bore and out from the bottom of the body, a float valve disposed in the flow bore below the fill valve assembly; such a fill sub wherein the float valve has a body with a top and a bottom and a fluid flow bore therethrough, a valve seat on the body, a valve member movably secured to the body for movement to seat against the valve seat to close off flow through the float valve and for movement away from the valve seat to permit fluid flow through the float valve, and a vent hole through the valve member for releasing fluid pressure build up beneath the valve member.
It is, therefore, an object of at least certain preferred embodiments of the present invention to provide:
New, useful, unique, efficient, non-obvious selectively actuable wellbore anchoring apparatus; such apparatus in combination with a whipstock; such apparatus and whipstock in combination with one or more mills; valve assemblies for selectively applying fluid under pressure to such apparatus; and milling systems and methods for single-trip milling operations;
A milling system and a mill with an auto fill apparatus;
A float valve with a vented valve member;
A device for releasably containing a charge of fluid for activating a wellbore apparatus;
A milling method in which a window is milled at a desired location in a tubular; and
A system for such a method.
This invention resides not in any particular individual feature disclosed herein, but in combinations of them and it is distinguished from the prior art in these combinations with their structures and functions. There has thus been outlined, rather broadly, features of the invention in order that the detailed descriptions thereof that follow may be better understood, and in order that the present contributions to the arts may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which may be included in the subject matter of the claims appended hereto. Those skilled in the art who have the benefit of this invention will appreciate that the conceptions, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the purposes of the present invention. It is important, therefore, that the claims be regarded as including any legally equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
The present invention recognizes and addresses the previously-mentioned problems and needs and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one of skill in this art who has the benefits of this invention""s realizations, teachings and disclosures, other and further objects and advantages will be clear, as well as others inherent therein, from the following description of presently-preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. Although these descriptions are detailed to insure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to claim an invention as broadly as legally possible no matter how others may later disguise it by variations in form or additions of further improvements.